Click here to access the full paper, 'Effects of intratracheally instilled laser printer-emitted engineered nanoparticles in a mouse model: A case study of toxicological implications from nanomaterials released during consumer use', as published in the journal NanoImpact.

Stewart Bland: I’d like to start by asking if you can introduce yourself and your group and tell us about your background.

Philip Demokritou: Okay, I’m Phillip Demokritou from Harvard University, the School of Public Health and I’m the director of the Centre for Nanotechnology and Nanotoxicology and also, another centre, funded by NIHS, the Centre for Nanosafety Research. So, my research focuses primarily on both implications of nanotechnology but also applications. So, the centres I mention there are a platform that bring together the people working on developing, designing new materials, nanomaterials and nanotechnology applications. And also, we’re trying to understand the fundamental nano-bio interactions and the potential environmental health and safety implications of nanomaterials.

My background is very diverse. Obviously, I’m a public health expert. That’s why I’m a faculty of the School of Public Health and its other section of engineering and life health sciences. Focusing, primarily, on understanding the pathogenesis of environmental industrial diseases. I’m based in the Department of Environmental Health Sciences at the School of Public Health and our research focus is primarily associated with the understanding the pathogenesis of environmentally-induced diseases.

Stewart Bland: That’s fantastic. Thank you. So, in your study, published in NanoImpact, you reported on the toxilogical implications of nanomaterials used by laser printers. Before we discuss the study, can you tell us why there’s concern over the safety of nanomaterials?

Philip Demokritou: Sure. You know, nanomaterials are unique because anything in the nanoscale, any material in the nanoscale has unique properties, in general. And those are physio-chemical properties, mechanical properties and that’s what makes them really unique for so many applications in every field of science. Now, on the other hand, nanoscale is the scale of nature. So, we do know now, because nanotoxicology (or nanosafety) this has been around for 10 or 15 years. We do have, really, reasons to worry that some of these materials… they can really, because of their size and their unique properties, they can really bypass biological barriers and they can interact with cells and can translocate from the rudimentary and can really be problematic.

Stewart Bland: So, in your study, you looked at particles emitted by laser printers. Just what are these particles and why did you decide to look at these?

Philip Demokritou: Yes, you know the new industrial model, as I already mentioned, is the nano-debedder, or other products or other applications out there. You know, industries, scientists like myself, we’re trying to take advantage of the unique properties in the nanoscale and a lot of products in the market currently, they’re nano in nature. So, this project actually started as a student project in one of my classes.

We started looking at products that, potentially, switched to nano and we started looking into toners, printing equipment, and we discovered (it wasn’t a big surprise for me) that these products, they were nano-enabled products. The industry, in the toner formulation, incorporate a lot of nano-additives there (for a reason, of course, to increase printing quality). And also, the problem that the industry had was the ozone generation from printing equipment, which was due to this corona that was used there to release ions to charge these large toner particles, so they can go and stick on the paper and make the printing perfect. So, they got rid of the corona and they switched to these nano-additives and especially metal oxides that, we do know, that they come with charge, on their own. So, they start switching and adding these nano-additives in their toner formulations. And, of course, they didn’t really pay attention, obviously, to those nano-additives that would be released during printing, which, as we confirm in many earlier studies, that’s the case.

So, that’s how we ended up studying these printer-emitted particles, which is a very complex mixture. You have all these nano-additives emitted and, more importantly, you have other gaseous co-pollutants, because the chemical composition of these toners is primarily organics and you have other gaseous components are needed and that’s how these PEPs are formed.

Stewart Bland: So, can you take us through how you approached the study?

Philip Demokritou: Yes, this is a big challenge in nanotoxicology. Assessing the risk of nanomaterials is: how do we link the real-world exposures beyond the pristine materials? Pristine nanomaterials to what people like you and I, as consumers, were getting exposed. So, you have the nanomaterials that... Usually nanomaterials are added in the product, in this particular case, it’s toner formulation and that’s what makes it a nano-enabled product. And across the life-cycle of this product there is a potential, for instance, during the consumer use, during printing in this case, for these nano-additives there to be released.

So, linking and studying the life-cycle implications of a nano-enabled product somatologically is not trivial. And that’s what we really want to link – these real-world exposures and, in this particular case, during consumer use to toxicology and, of course, assessing the risk. In order to assess the risks, you need not only the tox data, you need also the exposure data and that’s something usually… This nano-toxicology field doesn’t pay full attention.

So, this is the methodological power of the study, that we are linking to real-world exposure. We’re studying the release dynamics of these nano-additives and we’re trying to understand their biological properties and potential health implications.

There are many ways that we are doing this. We can use different experimental models. We build a platform that enables us to study the release dynamics in the lab and also, we use extensively different experimental models and those can be cellular models, to assess the mechanistic pathways for these particles. We collect these particles, size-fractionate them and look at their chemical composition. That’s very important information, especially if you try to apportion certain chemicals for certain health outcomes, you need to know the details of the exposures. So we characterise extensively the physiochemical properties of these printer-emitted engineered nanoparticles and through these various experimental models which can be cellular models or animal models like the study we published in NanoImpact. We’re trying to understand the toxicological implications.

Stewart Bland: So, what did you find in the study and should we be concerned?

Philip Demokritou: As I mentioned earlier, we’ve been working in assessing the properties of these printer-emitted engineered nanoparticles and also understanding the biological potential of these nanoparticles. So, we publish not only… this is a series of studies. The NanoImpact one is one of the latest ones we published.

But, just to summarise what we know: These PEPs, these printer-emitted particles, we proved that they are bio-active and they can elicit an array of unfavourable biological responses, both at the cellular level, but also at the organism level. Our latest studies, just to mention a few of these responses, include significant changes in cell viability. Also, we discovered some hereditary genetic material changes. We also showed that they can generate reactive-ox species and inflammatory responses.

So, all these outcomes they really show us that we need to pay attention for potential deleterious effects when these particles are inhaled. Of course, we need to still study more extensively and understand the mechanistic aspects, so we still have a lot of work to do. But I think these preliminary data from this series of studies make the case that when you see these kind of changes in the cellular environment and also at the people level and we do know that, generally speaking, exposures to environmental stressors can really be linked to serious health problems down the line. We can extend beyond the respiratory, but you can include cardiovascular diseases and other points.

Most importantly, this kind of implication study, we hope, will start the conversation with regulators, of course, to establish new guidelines for the safe use and toxicological screening of nano-enabled products across the life-cycle. We also hope that we’ll encourage the printing manufacturers to integrate hardware corrective measures to eliminate the release of nano-additives during printing.

Finally, I truly believe that assessing nano risk early on, during the material product development, when there is still a window to apply several design approaches, we’ll maximise the benefits of using nanoscale materials, but also eliminate potential environmental health implications. This is the way towards a more sustainable nanotechnology industry. Our society cannot afford developing and introducing new materials and chemicals into the market and cleaning the mess 30 years later, as we have done in the past. I think we really need to work together: researchers, regulators and industry to develop, in a more sustainable way, nanotechnology and new materials.

Stewart Bland: So, what’s next for this project?

Philip Demokritou: We have a number of studies, currently. We’re looking for… we’re focusing primarily on cardiovascular end points. And, just to make the case here, exposures from printing equipment in general, beyond laser printers, are happening not only at the office environment, but at the occupational level. In the United States alone, there are close to 150,000 workers in the photocopying industry. So, this is a major occupational hazard in addition to potential exposures at the office, or even at the home, micro environment.

So, we try to understand the potential for cardiovascular effects. One of the things we learnt from ambient particle toxicology, especially for ultra-fine particles also particles more or less of the same size, emitted from, primarily from compression sources. We do know that they are linked and we have a lot of epidemiological data linking these kind of exposures to cardiovascular effects.

So, when you inhale these particles, because they are tiny, they go deep into the lungs and they can really be translocated and we discovered that they can cause, among others, not just respiratory diseases but also cardiovascular effects. So, we have a project that focuses on assessing potential cardiovascular effects of PEPs. We’re also about to start a human health study in Singapore. This is a collaboration we have with Nanyang Technological University in Singapore to establish an occupational cohort and we will monitor workers in the printing industry over a course of time and try to understand the pathogenesis of certain diseases. So, this is, pretty much, the research agenda here for us.

Stewart Bland: Excellent. Thank you. So, finally, as always, I’d like to finish by asking: In your opinion, what are the hot topics in material science right now?

Philip Demokritou: That’s an endless list. In a way, the material research and nano is powering. I mean, the sky is the limit. I can mention a few areas that we are working. I truly believe that material research and, of course, nanotechnology in general can help our society to address a number of major issues. From food safety, that’s an area for instance, that we have a number of ongoing projects. Our society pays a huge bill in terms of foodborne diseases and also food waste and that’s where material science and technology can really play a significant role, developing new antimicrobial platforms, or even optimise the delivery of agrichemicals, that’s an area that can really make… we can make a difference. And we need new tools dealing with these kind of problems, which have been around forever of course. But, for whatever reason, we haven’t invested, as a society, developing new technologies dealing with microbes. So that’s an area, definitely, that material science can play a significant role.

Of course, the most exciting stuff is happening in the interplay of biology and engineering and I can mention a few areas: theranostics and developing novel approaches for theranostics. I think that’s another area we will see research in, in the years ahead.

But again, the sky’s the limit, so we need new materials, for energy applications and I think this is an exciting area of research to be in right now.

Dr Laura Indolfi speaks to Materials Today about her recent paper published in the journalBiomaterials. Follow the link below, to listen to the interview, or right click to download. Click here to read the article, A tunable delivery platform to provide local chemotherapy for pancreatic ductal adenocarcinoma.

Stewart Bland: I’d like to ask if you can start by introducing yourself, PanTher, and telling us about your background?

Laura Indolfi: Yes, so I am Laura Indolfi. I’m the founder and CEO of PanTher Therapeutics, which is a northerly state biotech start up based in Boston, Massachusetts, and we have revolutionised the way we deliver chemotherapeutic agents directly at the tumour site. I am a biomedical engineer. My training was in Italy, and then I moved to Boston to do my post doc at the Massachusetts Institute of Technology, and during my tenure there, we started this project in collaboration with oncologists at the Massachusetts General Hospital, to find a new way to treat cancer, and pancreatic cancer was one of our leading indications.

Stewart Bland: In your study published in the journal, Biomaterials, you reported on a new platform to provide local chemotherapy for pancreatic ductal adenocarcinoma. Before we discuss the development, can you tell us more about this condition?

Laura Indolfi: Yes, sure, so pancreatic cancer is a raising type of cancer. It has been established as the third leading cause of cancer deaths worldwide, just after lung cancer and colon cancer, and unfortunately, in the last 40 years, the survival rates of those patients hasn’t changed, so the diagnosis and the survival numbers for those tumour types are almost equal. Every year the same number of patients get diagnosed than the ones that died, so the treatments that there is right now on the table are definitely not effective. Because of the anatomical position of the pancreas, the tumour can spread, so it can enter into many vital organs that surround the pancreas, like the stomach, the liver, the coeliac nerves, and make the life of the patient very painful. So not only is it a tumour that’s spread very easily, but it also spreads in very vital organs, making the quality of life and prognosis very poor for those patients, so that’s a little bit of the general description of pancreatic cancer. Also it’s a very silent disease, so it gets diagnosed when it’s usually too big to be removed, leaving very few alternatives for those patients, other than the standard treatment, which is the injection of drugs into the bloodstream, with the aim that, in some magical way, going around throughout all of the body, they will find their avenue to go into the tumour mass, and be effective.

Stewart Bland: I think you touched on this in that answer, but could you say a little bit more about why it’s important to develop a new treatment for this particular condition?

Laura Indolfi: Yes, I touched a little bit, saying that it’s spread into other organs, but also I also said that the only treatment currently available is the systemic injection, so being able to deliver the drug into the bloodstream to reach the tumour mass. Unfortunately, for this particular condition, the tumours don’t have a lot of vessels within it, so if we think of the bloodstream as a highway that carries the drug to the tumour, we have no access to this highway into the tumour itself, so the drug goes everywhere else in the body, but very little will actually reach the tumour site. So we need a new treatment that can provide a better delivery of the weapon (the tumour therapeutic agent) directly at the tumour site to be effective. A lot of drugs have been designed and developed by a pharma company that can be very useful for pancreatic cancer, and also for many other types of solid tumours, but the inability of the drug itself to reach the tumour mass is what has been hindering the success of those drugs, so that’s where we kind of came along, and why we need this; it is important to deliver new localised treatment for pancreatic cancer, and many other solid tumours as well.

Stewart Bland: Now, can you tell us about the delivery device that you’ve developed, and what does it do, and how does it work?

Laura Indolfi: The interesting thing in our approach is that we have combined an engineer like myself, with the oncologists that treat those patients, and we have been very creative in trying to combine the two different knowledge bases to provide a solution for these patients, and what we have come up with is; we designed a platform that can be placed in direct contact with the tumour, and so is some sort of Trojan horse - so it’s a material which is very inert with the body, that can be placed in direct contact with the tumour, and over time the material itself will dissolve, and the drug will be released directly into the tumour mass, to increase therapeutic efficacy, and to decrease the systemic exposure, so the exposure of other parts of the body to the drug, that it’s usually the source of complications and side-effects. We designed our first product to be like a Band-Aid, as a patch, that can be placed, minimally invasive, in direct contact with the tumour, so the patients don’t need to undergo surgery. They can just have a laparoscopic procedure, where this patch can be folded in a cigar shape, and can then be unfolded on the other side of the catheter, to be wrapped like a blanket on top of the tumour, and this will serve as a two-fold weapon, on one side being able to place a solid blanket on top of the tumour, will help in preventing the continuous spreading of the tumour into other organs, so in case, where the tumour, it’s very confined, and has not yet invaded other organs, the ability to place this blanket will prevent the metastasis into the nearby organs, like the liver, the stomach, and at the same time, as the blanket will dissolve, the drug will be delivered in direct contact with the tumour, allowing for a better response to treatment that can shrink the tumour to a side where the surgeon feels confident that it can be removed.

Stewart Bland: So can you tell us a little bit about the testing of the device, and the success?

Laura Indolfi: So we have created these animal models, where we have implanted human tumours, human pancreatic tumours, into the pancreas of mice, and then once the microenvironment was recapitulated, so we have tumours into these mice in the pancreas, we either treated those animals with the standard of care of injecting the drug into the bloodstream for four weeks, or we placed it on top of the tumour, our mouse-sized prototype of the device, that was providing for a sustained release over the same time period of four weeks of the same drugs at the same concentration, so basically we wanted to test if the delivery method of the same amount of drugs, of the same drug, was going to have any effect of treatment, and in very good news and very surprisingly, we found that we were able to improve the response of treatment of twelve times, so the same amount of drugs, of the same drug, in the same animal model, but just delivered differently, allowed us to have a huge increase in the response to treatment, where the tumour has shrunk in dimension. They become very necrotic, so they were dead cells that could be easily removed in case of surgery, and we were also able to extend the survival rate of those animals, so the group that received the drug ivs, so into the bloodstream, they became sick very fast, and they died over a very short period of time, while the group that received our localised implant were able to live longer. Actually we had 100% to zero survival rate, so when all of the animals into the control group died, we had still all the animals alive in the localised delivery, that it’s a huge response for that tumour type, because the patients in the clinic, they have a very short life expectancy, so if we had the localised delivery, we can improve and prolong their survival rate, we will be affecting the life of thousands of patients worldwide, and another thing that we were not really expecting, but it’s going to be a very huge benefit for patients, is that we also showed that the ability of giving the drug locally at the primary tumour site affected the ability of the tumour to spread and metastasize also in a very distant part of the body, so when the animal group was treated with the drug injected in the bloodstream, they develop lung metastasis, while when we used our device for doing a localised delivery of the drug, because we were able to kill the primary source of the tumour, so the primary mass, there was no lung metastasis at the end of the study, and that’s because we are basically killing the primary source of the cells, and then they go around in the body and find another place, where to create their home, so this is something that will have a huge impact into the clinic, if we think of patients, that they can get diagnosed before the tumour has spread into other organs, they can have this blanket placed on top, shrunk to a size where the primary tumour can be removed, and also allow for prevention of the spreading into other organs, that then can cause a recurrence of the disease, or some more complication of the treatment, so all in all we had very good data that allowed us to be very enthusiastic about the possibility of bringing this treatment into the clinic for a disease that currently has a very poor outcome and no alternatives whatsoever.

Stewart Bland: So what's next for the project?

Laura Indolfi: So since then, we have spin out the company, PanTher Therapeutics, into our time at the MIT and MGH, because we want to bring this technology into the clinic. We are working very closely with the FDA to obtain all of the approval and the certification to start testing this treatment into the humans, so we are finalising a large animal model testing to be sure that the procedure of implantation in clinical settings, it’s safe and it’s reproducible, and if everything goes as we are planning in the next twelve months, we may be able to obtain FDA approval to start first-in-man clinical trials, and we can begin the testing into the patients. At the same time, we are also expanding the pipeline, so as I was mentioning at the beginning, all of this limitation of treating cancer, they are not only confined with pancreatic cancer, but most of the major solid tumours, colon, any type of gastrointestinal, solid tumour, they are very difficult to be reached by a surgeon, differently from what happens with breast cancer, for example, for all of this type of disease, an approach like ours, using our blanket to cover the tumour, and deliver the drug locally, can be very beneficial, so we are expanding beyond pancreatic cancer to make this treatment available for other types of disease as well, of the tumour site as well, and in parallel we are preparing a platform of agents that we can embed into this blanket, so we have chosen one drug that we have tested until now, but the beauty of this approach is that it’s a very versatile one, where we can put inside the blanket different types of drugs, even multiple drugs that can be released in a different way at different times, to provide a more comprehensive line of treatment for killing cancer, and making a new treatment solution for this disease, so we have a lot of work to go ahead, but we are very thrilled, and we are very galvanised by the early data that we have provided, so there is a lot of work to do, but we are very hopeful that we can bring a new solution for the treatment of cancer to the patients very soon.

Stewart Bland: Excellent, well that’s fantastic to hear. So finally, as always, I’d like to ask, in your opinion, what are the hot topics in materials science right now?

Laura Indolfi: I think that there is, I may be biased on that, because it’s the area where we are working on, but I really think that there is an untapped area of really providing a localised solution for delivering drugs, or for allowing regeneration of organs. Until now, medicine has been very focused on a systemic and whole body treatment for many diseases, and as material science progresses, and there is all of this combination of natural and synthetic material, or material that can recapitulate a biological clue, can sense a biological clue when inserted into the body and respond accordingly, this is a new area where materials science has a lot to bring on the table, to improve treatment in medicine, and I think that like us, many others are working in the field, we are really excited and intrigued to be at the forefront of engineering and medical science, to combine new material and old material reformulated, to have a huge impact in the development of new medical treatment in cancer and beyond.

Stewart Bland: I'd like to get started by asking if you'd please introduce yourself and your group and tell us about your background.

Michael Dickey: Sure, I'd be happy to. My name is Michael Dickey and I'm a Professor of Chemical and Biomolecular Engineering at NC State University in Raleigh, North Carolina and although my training is in polymeric materials and nanofabrication my group has been studying liquid metals for about a decade now. These materials are interesting because they are both liquids and metals. Most people think of mercury when they hear the term liquid metal, which is a bit unfortunate because mercury is known to be toxic. Instead, our group and others have been studying liquid metal alloys of gallium, which are considered to have low toxicity relative to mercury. Importantly these metals form surface oxides that act like a thin shell and this oxide shell allows the metal to be patterned and manipulated into shapes that would not be possible with conventional liquids like water. We have been studying these materials and taking advantage of their properties to make soft and stretchable electronics in our group.

Stewart Bland: So in your recent study published in Extreme Mechanics Letters you reported on a new method to create flexible wires using polymers surrounded by liquid metal. Before we get into the technical details of how, can you tell us about the need for flexible electronics?

Michael Dickey: I'd be happy to. There is a lot of interest right now in making electronics that are flexible and in some extreme cases, stretchable or even soft. There are at least two reasons I can think of for this interest. The first is just simply to give electronics greater functionality. A simple example of that would be a phone that could be folded for example. The second is to put electronics in places where it is currently difficult. An example of that might be some electronics on or inside the body, maybe within or on clothing or in other things that we come across in our daily lives. If you sort of take a step back and think about it, our bodies and many of the things that we interact with in our daily lives are soft and deformable and, in contrast to that, most electronics are made from rigid materials.

Ultimately there is a mechanical mismatch between the electronics that we have and our bodies and the things that we experience day to day. So, our group and a number of other groups around the world have been looking at ways to make electronics with interesting mechanical properties and we've tossed around a couple of words here - flexible, stretchable, and also soft, and if you think about flexible, it's possible to make electronics flexible by simply making the components thin and there are plenty of examples of this in our day to day lives. For example, aluminium foil is flexible because it is thin even though bulk aluminium is a very rigid material. In fact, you can make bicycle frames out of aluminium. We've been really trying to go a step beyond flexible electronics to try to make conductors that are stretchable and also soft.

Stewart Bland: So you used a liquid metal core surrounded by a polymer and that's a liquid metal at room temperature. Can you tell us a bit more about these exotic metals?

Michael Dickey: We're studying alloys of gallium. Gallium is directly below aluminium on the Periodic Table, which is another way to say that they are related and have similar properties but there is one major difference. That is that gallium has a melting point of approximately 30 degrees Celsius, which means that if you were to hold it in your hand your body is sufficiently warm to melt the metal and turn it into a liquid. In our case, we ensure that it stays as a liquid at room temperature by adding other metals to it. In this case we add indium and adding those things together lowers the melting point below room temperature to ensure that it stays liquid throughout our experiments and our application.

Liquid metals, as you may know, have very large surface tension and that causes them to want to beat-up to minimise their surface energy. If you've ever had the misfortune of breaking a mercury thermometer, you'll know that the mercury will beat-up into the shape of a sphere due to its large surface tension. So, this is really a problem if you want to pattern a liquid metal into a useful shape such as a wire, for example. There are other examples of this beyond mercury. Even water has a pretty large surface tension so if you were to turn on your faucet, you would see that a cylinder of water comes out of the faucet but it eventually breaks up into droplets due to surface tension. So, if you want to make a wire or something like that, that is stable, that's a challenge with liquid. Fortunately, gallium has a property that allows it to be patterned into stable shapes and that is that gallium reacts rapidly with air to form a thin oxide skin on its surface. The skin is only a few nanometres thick so it is quite thin, but it allows the metal to be moulded and manipulated into stable shapes that are none-spherical such as wires and, not quite a perfect analogy, but I like to say that the oxide skin is similar to how a water bed contains mostly water but yet it is held into the shape of a bed by a thin plastic bag that surrounds its surface and so this is sort of similar, but on a much smaller length scale.

Stewart Bland: So, how do you go about creating these wires?

Michael Dickey: Simply stated, we just place a droplet of liquid metal on a piece of putty and stretch it. This process is very much like stretching a piece of bubble gum and in our case, because the liquid is a metal, it stretches along with the putty. So, you stretch the putty, you also stretch the metal and the two things move simultaneously. When you do the stretching, the oxide skin breaks and reforms as you elongate it and again, to reiterate, without the skin the metal would just beat-up into a sphere or drop but with it the metal can form stable wire shapes. This whole process was inspired by the processes that are used to make fibre optic cables. In that process, a cylinder of glass is heated and simultaneously pulled into the shape of a fibre. In our case, we did not need to heat the materials because they were already soft at room temperature. The whole process is literally then at room temperature by hand. The resulting wires that we form consist of liquid metal encapsulated in polymer and in our work we explored several different putty-like materials including those that could be cross-linked after stretching to lock the structures into place. In other words, once you stretched it, you don't want it to be a putty anymore.

You want it to have found desired mechanical properties. Depending on the chemistries we employed, the wires could either be stiff or they could be elastic or rubber-like. We also showed it was possible to stretch the wires into a variety of shapes so they don't have to just simply be a straight line. It could be something you stretch out into the shape of a plus or a star or some other shape.

We also showed that you can control the diameter of the wires based on how far you stretch them. I think the smallest we got was about 10 microns diameter, which is about an order of magnitude smaller than the diameter of a human hair. So, the wires could be large but they could also be very small at the extreme.

Stewart Bland: So what kind of applications could these wires be suited to and are there any specific pros and cons?

Michael Dickey: This approach allows for wires to be formed on demand, which might be useful for repairs or for the military, for example to create antennas in the field of operation. The materials can be stored in a compact shape. They can be held in your pocket or in a bag and then be elongated into whatever shape is needed on demand. Now one of the limitations here or a drawback is that liquid metals are more expensive than typical wire materials like copper. Personally, I don't envision this concept to replace existing wires and it really only makes sense to use this approach if the added features justify the added cost.

Stewart Bland: So what's next for this project?

Michael Dickey: The wires that we formed were all done by hand, which limited the length of the resulting wires and also limited the reproducibility. Ideally, it would be preferable to also use machinery to do the elongation and that is something we are currently looking at. One of the important things that I would like to point out is that this work was all done by really excellent graduate students and also in collaboration with some of my colleagues in my department and I'm really thankful for all their efforts.

Stewart Bland: Fantastic. Well, to finish then, I'd like to ask, as always, in your opinion what are the hot topics in materials science right now?

Michael Dickey: Well, I'm going to show off some that I'm a little bit partial here because it’s an area that I'm personally interested in but I am partial to soft materials and I think there is genuinely a lot of interest in this topic right now for a number of reasons. Where I live in the research triangle in North Carolina there is a lot of interest at the universities that are in this region. I'll just give you an example. In our group, we are interested in soft conductors and actuators including the liquid metal we just talked about. The human body provides once source of inspiration for this work since the body has, for example, nerve networks, memory sensors and many other complex mechanisms that are built entirely from soft materials and there really are very few man-made analogues that can mimic what our body can do using soft materials yet it would be interesting to make systems like these to create new devices that have the functionality that we find in the body built entirely from synthetic materials and to make interesting devices.

Stewart Bland: Fantastic. Well, thank you very much for joining us today. It's been a pleasure talking to you.

Michael Dickey: It's been great, thanks a lot for having me.

]]>Tue, 31 Jan 2017 16:45:00 GMThttps://www.materialstoday.com/metals-alloys/podcasts/liquid-metal-wires/Sustainable Materials and Technologieshttps://www.materialstoday.com/energy/podcasts/sustainable-materials-and-technologies/
Laurie Winkless speaks to Dr Anthony Ku from GE Global Research, one of the Editor’s of the journal Sustainable Materials and Technologies, about his work, and the role of the journal.
Listen now]]>Sun, 13 Dec 2015 18:15:00 GMThttps://www.materialstoday.com/energy/podcasts/sustainable-materials-and-technologies/Ionic cable and Extreme Mechanics Lettershttps://www.materialstoday.com/mechanical-properties/podcasts/ionic-cable-and-extreme-mechanics-letters/
Interview with: The Editor of Extreme Mechanics Letters, Prof Zhigang Suo from Harvard University.

Prof Zhigang Suo from Harvard University, discusses the journal and his work on ionic cables: a new type of interconnect to fulfill the primary function of axons - transmitting electrical signals over long distances and at high speeds. Click here to read the full paper.